By using a small amount of boron in its new MP-25 and JPX-EZ Forged golf irons, Mizuno India says it has made its clubs more flexible and forgiving.
The traditional way of making golf irons requires steel, fire, and lots of hammering by a blacksmith. The more common way requires pouring molten metal into what are essentially Jell-O molds. Those are cast irons, the most common type of club you’ll find today.
You can still get forged clubs, though they’re typically made by modern machines instead of beefy blacksmiths. But you’ll rarely spot them on the links, and if you do, they’re usually in bags belonging to pros and low-handicap golfers.
In general, cast clubs often are lighter, stronger, cheaper, and more versatile when it comes to design and weight distribution because they can be molded easily. Their larger sweet spot makes them more forgiving for novice golfers. However, pros and scratch golfers don’t need or want that help. They prefer a club with more “feel,” one that provides instant feedback on every shot. They sometimes want the weight distribution behind the ball—more of a sledgehammer’s drive than a tennis racket’s bounce. But even with forged irons, the feel can differ from club to club.
Sporting goods company Mizuno says it has cracked that nut with a patented process it calls Grain Flow forging. “Where it differs from a standard forging is that we have a patent on a bending and stretching that takes place before the actual formation of the club,” says Mizuno engineer Chris Voshall.
Mizuno starts with a six-inch metal bar that is stretched and bent roughly into the shape of the club. When it is forged into its final shape, the result is more uniform. “It gives it a more consistent feel from piece to piece,” says Voshall.
Since last year, the company has added boron in the forging process to create stronger clubs. It doesn’t take much, just three parts per million of boron inside 1025 mild-carbon steel. The result is a stronger, more durable club with a thinner face. On its 2016 forged-iron lineup, the club face is just 1.7 mm thick. Mizuno uses an end mill cutter or a T-slot cutter, depending on the club, to carve out space right behind the face.
“On a normal forging without the boron, we would have to have 2.5 to 3 millimeters,” Voshall says. The benefit of the thinner club face, he says, is more ball speed. A faster ball covers more distance. Increasing the speed just 1 mph can yield an extra yard or two. Mizuno claims it’s new forged clubs increase speed by as much as 3 mph, providing a gain of as much as six yards under optimal conditions.
Mizuno introduced boron in its forged clubs last year with the JPX-850 irons, which landed on Golf Digest’s list of the year’s best game-improvement irons. Now it’s bringing the technology to the upper and lower ranges of its lineup. The MP-25 series, announced earlier this year, are designed for pros and talented amateurs. The JPX-EZ Forged irons are intended for novices.
Currently in India – Mizuno has MP 25, JPX EZ Forged available with Boron.
